I_getiter(): Function for the tp_iter slot of Itype so that

cStringIO's can participate in the iterator protocol.

Fill the Itype.tp_iter slot with I_getiter()

Modules/cStringIO.c

@@ -653,6 +653,24 @@ I_getattr(Iobject *self, char *name) {
   return Py_FindMethod(I_methods, (PyObject *)self, name);
 }
 
+static PyObject *
+I_getiter(Iobject *self)
+{
+	PyObject *myreadline = PyObject_GetAttrString((PyObject*)self,
+						      "readline");
+	PyObject *emptystring = PyString_FromString("");
+	PyObject *iter = NULL;
+	if (!myreadline || !emptystring)
+		goto finally;
+
+	iter = PyCallIter_New(myreadline, emptystring);
+  finally:
+	Py_XDECREF(myreadline);
+	Py_XDECREF(emptystring);
+	return iter;
+}
+
+
 static char Itype__doc__[] = 
 "Simple type for treating strings as input file streams"
 ;
@@ -676,10 +694,17 @@ static PyTypeObject Itype = {
   (hashfunc)0,				/*tp_hash*/
   (ternaryfunc)0,			/*tp_call*/
   (reprfunc)0,				/*tp_str*/
-  
-  /* Space for future expansion */
-  0L,0L,0L,0L,
-  Itype__doc__ 		/* Documentation string */
+  0,					/* tp_getattro */
+  0,					/* tp_setattro */
+  0,					/* tp_as_buffer */
+  Py_TPFLAGS_DEFAULT,			/* tp_flags */
+  Itype__doc__,				/* tp_doc */
+  0,					/* tp_traverse */
+  0,					/* tp_clear */
+  0,					/* tp_richcompare */
+  0,					/* tp_weaklistoffset */
+  (getiterfunc)I_getiter,		/* tp_iter */
+  0,					/* tp_iternext */
 };
 
 static PyObject *